[PATCH AUTOSEL 5.4 21/84] KVM: PPC: Book3S HV: Fix H_CEDE return code for nested guests

[PATCH AUTOSEL 5.4 21/84] KVM: PPC: Book3S HV: Fix H_CEDE return code for nested guests

[Sasha Levin]

From: Michael Roth <mdroth@linux.vnet.ibm.com>

[ Upstream commit 1f50cc1705350a4697923203fedd7d8fb1087fe2 ]

The h_cede_tm kvm-unit-test currently fails when run inside an L1 guest
via the guest/nested hypervisor.

  ./run-tests.sh -v
  ...
  TESTNAME=h_cede_tm TIMEOUT=90s ACCEL= ./powerpc/run powerpc/tm.elf -smp 2,threads=2 -machine cap-htm=on -append "h_cede_tm"
  FAIL h_cede_tm (2 tests, 1 unexpected failures)

While the test relates to transactional memory instructions, the actual
failure is due to the return code of the H_CEDE hypercall, which is
reported as 224 instead of 0. This happens even when no TM instructions
are issued.

224 is the value placed in r3 to execute a hypercall for H_CEDE, and r3
is where the caller expects the return code to be placed upon return.

In the case of guest running under a nested hypervisor, issuing H_CEDE
causes a return from H_ENTER_NESTED. In this case H_CEDE is
specially-handled immediately rather than later in
kvmppc_pseries_do_hcall() as with most other hcalls, but we forget to
set the return code for the caller, hence why kvm-unit-test sees the
224 return code and reports an error.

Guest kernels generally don't check the return value of H_CEDE, so
that likely explains why this hasn't caused issues outside of
kvm-unit-tests so far.

Fix this by setting r3 to 0 after we finish processing the H_CEDE.

RHBZ: 1778556

Fixes: 4bad77799fed ("KVM: PPC: Book3S HV: Handle hypercalls correctly when nested")
Cc: linuxppc-dev@ozlabs.org
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kvm/book3s_hv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 36abbe3c346df..e2183fed947d4 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3623,6 +3623,7 @@ int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
 		    kvmppc_get_gpr(vcpu, 3) == H_CEDE) {
 			kvmppc_nested_cede(vcpu);
+			kvmppc_set_gpr(vcpu, 3, 0);
 			trap = 0;
 		}
 	} else {
-- 
2.20.1

[PATCH AUTOSEL 5.4 31/84] powerpc/prom_init: Pass the "os-term" message to hypervisor

[Sasha Levin]

From: Alexey Kardashevskiy <aik@ozlabs.ru>

[ Upstream commit 74bb84e5117146fa73eb9d01305975c53022b3c3 ]

The "os-term" RTAS calls has one argument with a message address of OS
termination cause. rtas_os_term() already passes it but the recently
added prom_init's version of that missed it; it also does not fill
args correctly.

This passes the message address and initializes the number of arguments.

Fixes: 6a9c930bd775 ("powerpc/prom_init: Add the ESM call to prom_init")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200312074404.87293-1-aik@ozlabs.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/prom_init.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index eba9d4ee4baf6..689664cd4e79b 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -1761,6 +1761,9 @@ static void __init prom_rtas_os_term(char *str)
 	if (token == 0)
 		prom_panic("Could not get token for ibm,os-term\n");
 	os_term_args.token = cpu_to_be32(token);
+	os_term_args.nargs = cpu_to_be32(1);
+	os_term_args.nret = cpu_to_be32(1);
+	os_term_args.args[0] = cpu_to_be32(__pa(str));
 	prom_rtas_hcall((uint64_t)&os_term_args);
 }
 #endif /* CONFIG_PPC_SVM */
-- 
2.20.1

[PATCH AUTOSEL 5.4 32/84] powerpc/maple: Fix declaration made after definition

[Sasha Levin]

From: Nathan Chancellor <natechancellor@gmail.com>

[ Upstream commit af6cf95c4d003fccd6c2ecc99a598fb854b537e7 ]

When building ppc64 defconfig, Clang errors (trimmed for brevity):

  arch/powerpc/platforms/maple/setup.c:365:1: error: attribute declaration
  must precede definition [-Werror,-Wignored-attributes]
  machine_device_initcall(maple, maple_cpc925_edac_setup);
  ^

machine_device_initcall expands to __define_machine_initcall, which in
turn has the macro machine_is used in it, which declares mach_##name
with an __attribute__((weak)). define_machine actually defines
mach_##name, which in this file happens before the declaration, hence
the warning.

To fix this, move define_machine after machine_device_initcall so that
the declaration occurs before the definition, which matches how
machine_device_initcall and define_machine work throughout
arch/powerpc.

While we're here, remove some spaces before tabs.

Fixes: 8f101a051ef0 ("edac: cpc925 MC platform device setup")
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Ilie Halip <ilie.halip@gmail.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200323222729.15365-1-natechancellor@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/platforms/maple/setup.c | 34 ++++++++++++++--------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/platforms/maple/setup.c b/arch/powerpc/platforms/maple/setup.c
index 9cd6f3e1000b3..09a0594350b69 100644
--- a/arch/powerpc/platforms/maple/setup.c
+++ b/arch/powerpc/platforms/maple/setup.c
@@ -294,23 +294,6 @@ static int __init maple_probe(void)
 	return 1;
 }
 
-define_machine(maple) {
-	.name			= "Maple",
-	.probe			= maple_probe,
-	.setup_arch		= maple_setup_arch,
-	.init_IRQ		= maple_init_IRQ,
-	.pci_irq_fixup		= maple_pci_irq_fixup,
-	.pci_get_legacy_ide_irq	= maple_pci_get_legacy_ide_irq,
-	.restart		= maple_restart,
-	.halt			= maple_halt,
-       	.get_boot_time		= maple_get_boot_time,
-       	.set_rtc_time		= maple_set_rtc_time,
-       	.get_rtc_time		= maple_get_rtc_time,
-      	.calibrate_decr		= generic_calibrate_decr,
-	.progress		= maple_progress,
-	.power_save		= power4_idle,
-};
-
 #ifdef CONFIG_EDAC
 /*
  * Register a platform device for CPC925 memory controller on
@@ -367,3 +350,20 @@ static int __init maple_cpc925_edac_setup(void)
 }
 machine_device_initcall(maple, maple_cpc925_edac_setup);
 #endif
+
+define_machine(maple) {
+	.name			= "Maple",
+	.probe			= maple_probe,
+	.setup_arch		= maple_setup_arch,
+	.init_IRQ		= maple_init_IRQ,
+	.pci_irq_fixup		= maple_pci_irq_fixup,
+	.pci_get_legacy_ide_irq	= maple_pci_get_legacy_ide_irq,
+	.restart		= maple_restart,
+	.halt			= maple_halt,
+	.get_boot_time		= maple_get_boot_time,
+	.set_rtc_time		= maple_set_rtc_time,
+	.get_rtc_time		= maple_get_rtc_time,
+	.calibrate_decr		= generic_calibrate_decr,
+	.progress		= maple_progress,
+	.power_save		= power4_idle,
+};
-- 
2.20.1